As I mentioned before. I
have not needed a crupper on my horse and only seldom used one on
really tough rides as "insurance". I've never used breast collars on my
horses. And if I was having a lot of trouble with a saddle sliding
around on my horse, I would really be looking things over to see what
was going on.
But a mule is not a horse. Which is what I am riding now. Mother nature
did not leave anywere for a saddle to settle on a mules back. (maybe
it's because mother nature didn't make mules ..... LOL) Their extremely
straight backs don't leave anywhere for a saddle to settle into. It's a
rare mule that can be ridden without crupper and breastcollar. Many
need a full britchin to keep a saddle in place.
Mother
nature is a wonderful woman, but she is also very stubborn. When you
put the saddle and girth on and start down the trail there are forces
that are acting on that saddle. Eventually that saddle will move to
best balance those forces. So where "I want it" may have nothing to do
with it is going to be. Mother nature will always win this battle.
I think the first thing to do is figure out where the saddle is going
to end up on it's own. Then figure out why, e.g., the girth grove is
very far forward, long shoulder, uneven shoulders, uphill or downhill
build, the saddle is too wide or too narrow or too long, etc. Once you
understand the problem a solution is a lot closer.
As far as a crupper - I've never used one on the two horses I've
primarily ridden the past 17 years. I've ridden on the Florida flat to
steep ridges of the OD to the gullies and ravines of Alabama to climbs
over 12,000 feet in Colorado. Never had an issue with the saddle going
forward on either horse.
Actually I very seldom used a breast collar on these horses either. I
was lucky with both. The were both very well balanced and once I found
a saddle that fit - it stayed in place.
If I had to use extra tack to keep a saddle in place - it's time to
figure out what is causing the saddle to move and go from there.